What is in this article?:
- The discovery of citrus greening disease on an orange tree in a commercial grove in the Texas Rio Grande Valley last week is unsettling to growers.
- Comprehensive management plan, extensive surveys and preventive control measures over the last three years gives local growers reason for hope.
- The Texas Department of Agriculture announced a five-day emergency quarantine surrounding the infected tree.
Ray Prewett, President of Citrus Mutual in Mission, says most researchers and growers are not surprised the disease has spread to the Texas Valley. Valley citrus growers have been involved in a comprehensive management program in recent years to control Asian psyllid populations in an effort to curtail the chances of infection, and Prewett says he is hopeful the disease is not widespread.
“Psyllid populations in the Valley are currently at the lowest levels they have been for sometime thanks to grower participation in a comprehensive management and control program, and they should be commended for their active role in a program that added to their production costs though the disease had not been detected until now,” Prewett says. “Federal support has been available for infrastructure but the growers have been bearing the cost for psyllid control and treatment.”
Nearly 85 percent of commercial groves have participated in the psyllid control program, an effort involving dormant spray applications, especially during cooler weather months. But a number of factors including recent rains, mild temperatures, high winds, irrigation and a continuing harvest have made the first dormant spray window smaller and the task difficult to achieve.
“Numerous folks are reporting that our citrus acreage may not have achieved true dormancy this winter, and there are ongoing reports of flush development and psyllid activity now,” Citrus Mutual’s Bret Erickson explained to Valley growers in an email on Jan. 5. “Thanks to your efforts, the past year’s overall psyllid populations have been at their lowest recorded levels.”
Erickson had warned growers not to rely only on visual checks or traps for psyllid populations and suggested scouts tap sample trees in their grove. Research has shown that during the winter months psyllids are more likely to move inside the canopy and not be as mobile. It appears it was one of these samples that uncovered the disease in a grove near San Juan, located near the Texas-Mexico border.
Prewett and Mangan agree that Valley growers have learned a great deal about citrus greening by monitoring its devastating effect on Florida citrus in recent years and as a result of extensive research conducted by USDA’s Weslaco research center and by Texas AgriLife scientists. Both say they remain hopeful the disease can be contained and controlled.
“One of things USDA and the Texas Department of Agriculture are looking at is the ability of regulatory agencies to lawfully remove the infected trees. But Valley growers are well aware this is the best way to curtail spread of the disease and they are expected to voluntarily participate in whatever measures are required to prevent widespread infection,” Mangan said.